Commitments (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Commitments [Abstract]
Total net rent expense	$ 18,300,000	$ 13,600,000	$ 10,100,000
Net Operating Leases
2014	11,680,000
2015	7,557,000
2016	2,435,000
2017	1,488,000
2018	1,428,000
Thereafter	1,718,000
Total minimum payments	26,306,000
Other Contractual Obligations
2014	1,020,000
2015	1,008,000
2016	550,000
2017	550,000
2018	550,000
Thereafter	0
Total minimum payments	$ 3,678,000